#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
class Solution{
    public:
    bool containsDuplicate(vector<int>& nums) {
        sort(nums.begin(),nums.end());
        int n=nums.size();
        for(int i=0;i<n-1;i++)
        {
            if(nums[i]==nums[i+1])
            {
                return true;
            }
        }
        return false;
    }
};
int main(){
    vector<int> nums = {1,2,2,3,4,5};
    Solution s;
    cout << s.containsDuplicate(nums) << endl;
}
 